Collapsible cargo container

ABSTRACT

A collapsible container is provided with two side walls, each formed in two hinged sections, with the lower of the sections being hinged to a base. These walls are capable of collapsing from an erect position inwardly to overlie the base. With the side walls erect, a pair of flexible end walls of slat construction is removably disposable in tracks bounding the periphery of the side walls. The slats are hinged together and have overlapping adjacent edges to present a weather barrier. The tracks and end walls are provided with mating flanges and grooves to effect a structural interlock in the erected container. Alternately, rollers disposed in a grooved track may be used to effect a structural interconnection of the end walls through the side walls. A removable ridge beam is disposed intermediate the tracks to provide a guide which tracks or untracks the end walls in their installation and removal as well as in the opening and closing of the container.

United States Patent [191 Cole, deceased 1 Jan. 9, 1973 [54] COLLAPSIBLE CARGO CONTAINER [76] lnventor: Hayward C. Cole, deceased, late of 23225 Carlow Road, Torrance, Calif. 90213 by LVina Cole, executrix [22] Filed: April 23, 1971 [21] Appl. No.: 137,009

Related US. Application Data [63] Continuation of Ser. No. 56,167, July 8, 1970, aban- Primary Examiner-Raphael H. Schwartz Attorney-Christie, Parker & Hale [57] ABSTRACT A collapsible container is provided with two side walls, each formed in two hinged sections, with the lower of the sections being hinged to a base. These walls are capable of collapsing from an erect position inwardly to overlie the base. With the side walls erect, a pair of flexible end walls of slat construction is removably disposable in traclts bounding the periphery of the side walls. The slats are hinged together and have overlapping adjacent edges to present a weather barrier. The tracks and end walls are provided with mating flanges and grooves to effect a structural interlock in the erected container. Alternately, rollers disposed in a grooved track may be used to effect a structural interconnection of the end walls through the side walls. A removable ridge beam is disposed intermediate the tracks to provide a guide which tracks or untracks the end walls in their installation and removal as well as in the opening and closing of the container.

17 Claims, 9 Drawing Figures PATENTEUJAN 9 97s SHEET 1 [IF 3 PATENTEDJAN 9 I975 3.709.396

' SHEET 3 BF 3 BACKGROUND OF THE INVENTION The present invention relates to cargo containers in general, and in particular, to an improved, collapsible cargo container suitable for use in aircraft.

Freight or cargo transport by aircraft is becoming increasingly popular. To suit the peculiar requirements of air cargo transport, cargo containers are used.

Aircraft cargo containers offer the air freight industry the vehicle necessary to effect rapid aircraft loading and unloading while satisfying cargo flight requirements. Cargo loading and unloading is facilitated by the ability to load and unload containers at locations remote from the carrier aircraft, a procedure which saves considerable aircraft flight time because individual piece handling aboard an aircraft is not required. Moreover, cargo containers are used to group cargo according to common destination and thus to avoid the time consuming task of individual piece location and removal. Containerization is also used to produce the necessary load distribution for flight stability.

in effecting these ends, aircraft cargo containers must present a strong barrier between cargo and an aircrafts interior. This barrier is necessary to prevent cargo jamming against the interior walls of an aircraft which could result in structural damage and difficulties in cargo unloading. Moreover, the barrier is necessary to avoid time consuming cargo tie-down and in-flight cargo shifting.

Of known aircraft cargo containers, the so-called hula huts and igloos" have gained acceptance because they have proven to be a satisfactory resolution of many containerization requirements. These containers are rigid, noncollapsible structures having an open loading and unloading end usually closed by a net. The lack of a rigid closing wall suffers the disadvantages of cargo shifting fore and aft during flight, the possibility of cargo locking with an adjacent container and the possibility of loss through pilferage. Another problem with these types of containers is the relatively limited open-side area available for loading and unloading cargo. The open side of the container is made small because of the necessity of a relatively expansive roof to rigidly interconnect their walls. The small access area makes top loading essentially impossible and side loading difficult. I

One of the most severe problems confronting the air freight industry with known cargo containers is that the containers are not readily collapsible into compact, easily transportable units. Many areas receive more air freight than they generate. Such areas tend to accumulate cargo containers. On the other hand, many areas generate more air freight than they receive. As a result, there is often a deficiency of cargo containers in net air freight export areas. As a consequence, and for the economical utilization of available containers, it is necessary to transport empty containers to areas requiring them. Because containers such as hula huts" and igloos" are not readily collapsible, maximum utilization of available aircraft capacity has not been possible in container shipment to container deficient areas.

Thus, there is an immediate requirement for an easily collapsible aircraft cargo container which is structurally sound, totally encapsulates its cargo, and which presents a large cargo access area.

SUMMARY OF THE INVENTION The present invention provides a readily collapsible cargo container for use with aircraft which totally encapsulates its cargo, is structurally sound, and which is capable of providing a large cargo access opening.

One form of the present invention contemplates a collapsible cargo container having; a base, a pair of side walls and flexible end walls. The base may be in the form of a standard pallet. The side walls are hinged to the base for disposition between a collapsed storage position and an erect in-use position. Each side wall may further be formed of an upper and a lower section hinged together to fold over one another yvhen stored. The flexible end wall is of slat construction. The slats are coupled together, as by hinges, along their lengthwise edges to provide the end walls flexibility. Means are provided, such as a flange and groove sliding connection between the slats and the side walls, to rigidly interconnect the side walls through the slats of the end wall. These means are associated with end wall tracks disposed about the peripheral edge of the side walls.

In more specific form, the present invention contemplates the use of two cooperating end walls and a ridge beam which is removably disposable between the side walls. This ridge beam provides a closure between end walls and a guide for the removal and insertion of each end wall from and into the tracks. An end wall may then be conveniently disposed over its associated end wall during cargo loading and unloading. This facility offers a large cargo access opening at either end of the container without adversely affecting the erection stability of the container, the in-place end wall providing a structural interconnection of the side walls.

For purposes of erection and side wall bending stability when erected, the present invention contemplates the use of means such as doublers at the hinge joints between the upper and lower side wall sections. The doublers provide fastening anchors and bearing mem bers to couple the side wall sections into an effectively unitary whole. For ease in erecting the cargo container of the present invention, base doubler means are employed which have a bearing, surface displaced somewhat off the vertical. These base doublers provide bearing members to aid in maintaining the side walls erect during assembly and a fastening base for fasteners used to hold erect lower side wall sections rigidly in place.

As was previously mentioned, the end wall and track have means for effecting a rigid, erect structure by rigidly coupling the side walls together through the slats of the end walls. These means may be flanges disposed in a continuous recess or groove such that displacement forces normal to a side wall are transmitted to the slats and ultimately to the complementary side wall. If desired, this type of rigid construction may be effected with rollers disposed in a groove to effect the desired force coupling of the side walls through theslatted side walls.

Because it is desirable to have the cargo container weatherproof, it is preferred to have the hinged coupling between individual slats protected by an overlapping, rotatable sealing joint formed in the slats themselves.

Air freight cargo containers must be as light as possible to maximize aircraft payload. To this end, it is preferred to fabricate the slats and end walls from a light but very strong material and to utilize structural configurations of the slat to augment strength. Suitable material for slat and side wall construction is plastic reinforced fiberglass. This material, having a strength on the order of 50,000 p.s.i. in tension, may be readily formed into structurally shaped slats by the so-called pulltrusion process. The pulltrusion process is also suitable to form the sealing joints.

One of the unique features of the present invention is the ability of the cargo containers to be collapsed into a compact unit. This is readily accomplished in a preferred form of the present invention by constructing the side walls such that they double on themselves and fold into a position overlying the base with the end walls disposed beneath them. The ridge beam is conveniently stored above the end walls and between the folded side walls.

The cargo container of the present invention provides an extremely rigid and strong cargo-containing structure which is readily adapted to a variety of aircraft configuration requirements. The structural integration of the side walls, through removable and flexible end walls, assures the integrity of the container. The end walls, being flexible, may conform to a variety of exterior configurations. The side and end walls of the present invention completely enclose the containers interior and therefore eliminate the open side attendant with the hula hut and igloo" type containers. By structurally integrating the container through the end walls, an extremely large area for loading and unloading cargo may be provided.

These and other features, aspects and advantages of the present invention will become more apparent from the following description, appended claims and drawings.

DESCRIPTION OF THE FIGURES FIG. 1 is an end elevational view of a preferred form of the cargo container of the present invention;

FIG. 2 is a view taken along line 22 of FIG. 1 showing one of the end walls displaced from its closed position;

FIG. 3 is an end elevational view depicting the collapse of the container for storage or shipment;

FIG. 4 is a fragmentary end elevational view similar to that of FIG. 2 showing an end wall being inserted over the base of the container for storage when the container is collapsed;

FIG. 5 is a side sectional view of the preferred construction of the end walls of the present invention;

FIG. 6 is an end, fragmentary elevational view through the ridge beam showing the ridge beam in its in-use position;

FIG. 7 is a fragmentary view depicting one form of a track suitable for the present invention;

FIG. 8 is a view similar to FIG. 7 showing an alternate form of the track ofthe present invention; and

FIG. 9 is a view similar to FIGS. 7 and 8 depicting yet another alternate form of the track of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The collapsible container depicted in the first three Figures, indicated in general by reference numeral 10, includes a base 12, a pair of side walls 14 and 16, and a pair of end walls 18 and 20.

The base is preferably in the form of a standard aircraft pallet adapted for the mounting of the side walls.

Side wall 14 has an upper section 22 and a lower section 24. These upper and lower sections are hinge-coupled by a laterally extending hinge 26 to allow side wall 14 to collapse on itself. Side wall 16 is similarly constructed of a lower section 28 and an upper section 30 and is capable of doubling on itself through a laterally extending hinge 32. The side walls are preferably fabricated from plastic reinforced fiberglass.

Means is provided for each side wall to effect a rigid coupling between the upper and lower side wall sections in their erect position. The means may be in the form of a doubler for each side wall. Doubler 34 illustrated for side wall 14 is typical of both doublers. Doubler 34 is rigidly secured to upper section 22 and is removably securable to lower section 24, in the erect position, by a plurality of fasteners 36.

Each side wall is hinged to base 12 through a hinge such as hinge 38 shown in FIGS. 2 and 4 for side wall 14. A complementary hinge 40 for side wall 16 is identical to hinge 38 in its function and is therefore not shown in detail. Hinge 38 allows side wall 14 to drop over base 12, as seen in FIG. 3. Hinges 38 and 40 are secured respectively to lower sections 24 and 28 and vertical side wall extensions 42 and 44. Side wall exten sions 42 and 44 are affixed to base 12 and extend across the width of the side walls.

Each side wall has a track for end walls 18 and 20. As will be described in detail subsequently, these tracks ef feet a rigid interconnection of the side walls through and with the end walls to effect an extremely high strength but lightweight cargo container. The track of side wall l4 is shown in general by reference numeral 45.

Each track has an overcap 46, 48, which defines the peripheries of side walls 14 and 16. Four upstanding track extensions are affixed to the four corners of base 12. Three of these extensions are shown and indicated by reference numeral 50. These extensions define continuations of the tracks below hinges 38 and 40. The junction between overcaps 46 and 48 and the track extensions is provided with a slight recess or notch 56 for the passage of the end walls into and from their storage position. Each track extension has a vertical tracking groove 58 which is defined by an overcap portion 60 and a backup portion 62. The lower ends of the tracks and track overcaps extend at a 45 angle to the notch. Similarly, the upper end of the track extensions are angled at 45 from the notch to define with the tracks and track overcaps a rotation space between the side wall erect and side wall collapsed positions. Each side wall, then, is capable of collapsing inwardly to overlie the base. The location of the side wall hinges above the base develops a space below the collapsed side walls for storage of the end walls, as is clearly depicted in FIG. 3.

A ridge beam 64 is provided between the side walls. This ridge beam does not provide a structural coupling of the end walls, but instead provides continuity of closure and serves as a means for guiding each end wall 18, out of its track or into its track. Thus, in FIG. 2, ridge beam 64 has a flat, triangular cross section, with upper surfaces disposed to direct the end walls into and out of their tracks.

As is also shown in FIG. 2, the ridge beam guides each end wall into a position overlying the complementary end walls track overcap. Thus, end wall 18, as shown, is disposed on the portion of overcap 46 which receives end wall 20. It should be noted that an end wall can be almost completely removed from its track to provide a considerable access area to the interior of the erected cargo container while retaining the end wall with the container. As is seen in FIGS. 2 and 6, ridge beam 64 is removably inset into both side wall tracks in a recess 67. Overcap 46 is provided with a recess 65 to permit removal and placement of either end wall. An identical recess in overcap 48 complements the function of recess 65. The recess in the overcap is such that side walls 14 and 16 must be displaced slightly outward to accept ridge beam 64.

Doublers 66 and 68 are provided to aid in the erection of the cargo container. These doublers are permanently affixed in position to base 12 and have a slight outward flair, depicted in FIGS. 1 and 3, to aid in positioning the side walls during their assembly, and allow placement and removal of ridge beam 64, a procedure which will subsequently be described. These doublers also act as a fastening base for fasteners 70. When the fasteners are secured in doublers 66 and 68, the side walls are rigidly secured to the base.

To provide considerable cargo access area and a rigid container, end walls 18 and 20 are fabricated from individual slats 72 and are made flexible. As is seen in FIG. 5, flexibility is effected by interconnecting the longitudinal edges of each slat 72 of the end walls with a plurality, say four, hinges 74. Hinges 74 prevent longitudinal displacement of slats 72 with respect to one another. Thus, the hinges serve to transmit longitudinal loads throughout the end walls.

To effect a weatherproof joint at the hinge connections between slats, adjoining slats are constructed to provide an overlapping mechanical seal along the longitudinal length of the slats. This overlapping joint is effected in the present invention by an underlying lip 76 and an overlying lip 78 of an adjoining slat. The end walls are disposed in their tracks such that edge 80 of overlying lip 78 faces down. Thus, water cannot enter between the wiping surfaces of the joint. To provide the requisite joint flexibility, the wiping surfaces of lips 76 and 78 describe an arc ofa common circle.

In order to provide a light cargo container, each slat has a raised intermediate portion 82 which merges into end sections 84 and 86. As is known, this type of construction provides considerable rigidity against bendmg.

A suitable material for slat construction is plastic reinforced fiberglass. A suitable process for forming the slat is known as the pulltrusion process.

If desired, locks (not shown) may be incorporated to lock the end walls to the base.

While considerable structural integrity of container I0 is effected through the use of the doublers and fasteners in the side walls, the present invention provides a cargo container which structurally interconnects side walls 14 and 16 through end walls 18 and 20 to maximize its strength. This interconnection is effected by conjoining the side walls with the end wallsin such a manner that inward or outward forces on one side wall are transmitted to the slatted end walls and re sisted both by the inherent lateral rigidity of the end walls and by the interconnection between the end walls and the complementary side walls.

This structural interconnection may be effected by the constructions shown in FIGS. 7 through 9.

In FIG. 7, each of the side walls previously described has an arch section 88 integral with the balance of the wall. This arch section provides an upper bearing surface 90 for slats 72. An overcap or arch cap 92, corresponding to overcaps 46 and 48, is attached at regular intervals by fasteners 94 to arch 88. the overcap has a downwardly extending flange 96 which is loosely received in a slot or groove 98 of the slats. This slot is in end pieces I00 which are secured, as through rivets 101, to the slats. The track for the end walls is then defined by bearing surface 90, flange 96 and groove 98. Forces tending to move end pieces 100 towards the right in FIG. 7 engage the left-hand vertical wall of groove 98 with flange 96 of overcap 92 to transmit these forces through the overcap to the side wall. Conversely, forces directed to the left :in FIG. 7 engage the end portion with the overcap to transmit such tensile forces directly through the arch cap to the end wall.

The construction of FIG. 8 is similar to that in FIG. 7

except that a flange I02 of the track is made integral with an arch 103 of the side wall. The end piece of each slat, indicated by reference numeral 104, is provided with the complementary groove or recess 105. This recess receives flange I02. On each side of flange 102 is a bearing surface of arch I03 for end pieces 104. As before, slats 72 are connected to their end pieces through rivets Hill. An overcap or arch cap 106 is pro vided with an upstanding flange 108 to provide an overriding track for end walls being removed or inserted into their normal track position, as when cargo is being stored, removed, or the container is being erected or collapsed. The track for slats 72 in the FIG. 8 embodiment is defined by the upper bearing surface of arch I03, flange I02 and overcap 106, the latter serving to retain the side walls in place. The FIG. 8 construction has the advantage of providing greater impact protection for the underlying track than is provided in the FIG. 7 embodiment.

FIG. 9 depicts a construction suitable when rollers or wheels are desired. As before, each end wall has an arch 110 formed integral therewith. Again, an arch or overcap I I2 is provided to protect the track and to provide an overriding track for removing or inserting a complementary side wall. Each slat 72 mounts an offset wheel or roller 114 through an axle 116 which is secured in the slats by a nut I18. Arch 110 is provided with a continuous groove 120. Groove I20 presents vertical bearing surfaces for wheel 114 to force couple the side walls through the slats.

FIG. 6 shows still another means; for rigidly interconnecting the side walls through the end walls. In this Figure, each slat 72 has an end portion 122. An upstanding flange I24 of end portion 122 is disposed inwardly of downwardly extending flange 126 of overcap 46. Flange 126, then, defines a tracking groove and a load bearing member for flange 124. The construction shown in FIG. 6 corresponds to the generalized tracks and side wall interconnections shown in FIGS. 1 and 2.

The cargo container depicted in FIGS. 1 and 2 is fully erected. In this position, access to the interior of the container may be readily had by sliding either end wall 18, over ridge beam 64 such that they rest on overcaps 46 and 48.

When it is desired to collapse the cargo container, each end wall is removed in the fashion shown in FIG. 2; that is, the end walls are removed from their tracks by overriding the ridge beam. After each end wall is removed, it is inserted through notches 56 onto the base. This is clearly shown in FIG. 4. Ridge beam 64 is then removed and placed in the middle of the end walls as is shown in FIG. 3. The lowering of each side wall is initiated by unloosening the fasteners of doubler 34 of said wall 14 and the fasteners for the doubler of side wall 16 to free the upper and lower sections of the side walls from each other. The couplings between lower sections 24, 28 and upstanding doublers 66, 68 are then removed by loosening fasteners 70. The side walls are then capable of folding, as shown in FIG. 3, from the erect to the stored positions, with the upper sections lying on their corresponding lower sections.

When it is time to erect the cargo container, the reverse procedure is generally followed. Briefly, each side wall is raised and the fasteners installed in the doublers between their upper and lower sections. Ridge beam 64 is placed in its recess to span the space between the erect side walls. The flair of doublers 66 and 68 provide for some side wall shifting to accommodate the placement of the ridge beam. The fasteners are then installed between base doublers 66 and 68 and lower sections 24 and 28. End walls 18 and 20 are then removed through notches 56 and inserted into their respective tracks with the aid of the guiding surfaces of the ridge beam.

It should be noted that the cargo container of the present invention may take any number of desired shapes. For example, the container can be box-shaped or split along the longitudinal centerline of the embodiment illustrated. Variations in the ratio of container height to width can be accommodated by varying the number of hinged folding elements in each side wall.

What is claimed is:

1. A collapsible cargo container for use in aircraft comprising:

a. a flat base to support cargo;

b. first and second spaced-apart and rigid side walls,

each side wall being hinged to the base for disposition between a collapsed storage position and an erect position substantially normal to the base and parallel to the other side wall;

c. a track associated with each side wall, each track being disposed about at least a substantial portion of the edge of its associated side wall;

d. atleast one end wall formed of individual, rigid slats flexibly interconnected along adjacent lengthwise edges, the end wall being slidably 6 disposable in the tracks when the side walls are erect;

e. means associated with the, tracks and the end wall to rigidly and nonrotationally couple the side walls together in their erect position through the end wall, such means consisting of a flange and groove rigid interconnection between the end wall and each of the tracks, the flange and groove interconnections providing the sole interconnections between the side walls and end wall and being such that loads on one side wall are resisted by both side walls acting in combination with the end wall; and

f. wherein each side wall has a lower and an upper section hinged together such that one section is capable of folding over the other section into a collapsed position, and means is provided to rigidly couple the two sections together in the erect position.

2. The cargo container claimed in claim 1 wherein the rigid coupling means comprises a doubler affixed to one of the sections and adapted to be rigidly secured to the other section when the side walls are erected.

3. The cargo container claimed in claim 2 wherein an upstanding doubler attached to the base is provided for each side wall and means is provided to rigidly couple the lower sections of the side walls to such upstanding doublers.

4. A collapsible cargo container for use in aircraft comprising:

a. a base to support cargo;

b. first and second spaced-apart and rigid side walls,

each side wall being coupled to the base for selective positioning in a stored position overlying the base and an erect position substantially normal to the base and parallel to the other side wall;

c. a track on each side wall, each track being disposed about at least a substantial portion of the edge of its associated side wall;

d. first and second end walls formed of individual rigid slats flexibly interconnected along adjacent lengthwise edges, the end walls being removably and slidably disposable in the tracks of the erected side walls with the slats normal to the side walls, the end walls being capable of bounding substantially the entire ends and top of the container in a closed position;

e. means associated with the tracks and the end walls to rigidly and nonrotationally couple the side walls together in their erect position through the end walls, such means consisting of a flange and groove rigid connection between the end walls and each of the tracks, the flange and groove connections providing the sole interconnections between the side walls and the end walls and being such that loads on one side wall are resisted by the side walls acting in combination with the complementary end walls; and

f. wherein each side wall has a lower and an upper section coupled together such that one section is capable of being folded over the other section in the stored side wall position, and means is provided to rigidly couple the two sections together in the erect position.

5. The cargo container claimed in claim 4 wherein an overcap is provided for each track, the overcaps having a recess disposed to permit each end wall to be moved from its closed position to a position overlying the other end wall and resting on the overcap associated with such other end wall.

6. The cargo container claimed in claim including a ridge beam, the ridge beam being removably disposable in the recess of the overcaps and between the side walls, the ridge beam providing guiding surfaces for the end walls during their removal from and insertion in the tracks.

7. The cargo container claimed in claim 5. wherein the coupling of the side walls to the base is provided by hinge means between the lower sections of the side walls and the base, and means is provided to nonrota tionally couple the side walls to the base in their erect position.

8. The cargo container claimed in claim 7 wherein a track extension for the end walls is provided below the hinge connection of the lower sections of the end walls to the base, the lower end of the overcaps and tracks and the upper end of the track extensions defining a slot for removing and placing the end walls from and into a stored position overlying the base.

9. The cargo container claimed in claim 8 wherein the hinge connections of the lower sections of the end walls to the base are such that the side walls in their stored position are spaced from the base to provide a space for storage of the end walls.

10. The cargo container claimed in claim 9 wherein upstanding doublers are provided on the base, the doublers being canted slightly outward from the vertical to provide ease of side wall erection, the nonrotational coupling means including the doublers and fastening means to rigidly attach the side walls to the doublers.

11. The cargo container claimed in claim 5 wherein each end wall slat is provided with an underlying lip exedge thereof, the overlying and underlying lips of adjoining slats being disposed with each other to provide a weatherproof, flexible joint between slats.

12. The cargo container claimed in claim 5 wherein the slats of the end walls are longitudinally rigidly interconnected.

13. The cargo container claimed in claim 12 wherein the rigid coupling means includes flange and groove connections between the slats and the tracks, the flange and groove connections being such that loads on one side wall are resisted by the side walls acting in combination with the complementary end walls.

14. The cargo container claimed in claim 13 wherein the flange and groove connections are provided by a continuous groove in end sections of the slats and a continuous mating flange of the tracks.

15. The cargo container claimed in claim 13 wherein the flange and groove connections are provided by continuous grooves of the tracks and mating flanges on end sections of the slats.

16. The cargo container claimed in claim 14 wherein the overcaps have an upstanding flange adapted to mate with the groove of the slats to provide a positive track for the end walls disposed on the overcaps.

17. The cargo container claimed in claim 5 wherein the rigid coupling means includes rollers disposed in grooves having bearing edges engageable with the rollers to transmit loads from the side walls to the slats. 

1. A collapsible cargo container for use in aircraft comprising: a. a flat base to support cargo; b. first and second spaced-apart and rigid side walls, each side wall being hinged to the base for disposition between a collapsed storage position and an erect position substantially normal to the base and parallel to the other side wall; c. a track associated with each side wall, each track being disposed about at least a substantial portion of the edge of its associated side wall; d. at least one end wall formed of individual, rigid slats flexibly interconnected along adjacent lengthwise edges, the end wall being slidably disposable in the tracks when the side walls are erect; e. means associated with the tracks and the end wall to rigidly and nonrotationally couple the side walls together in their erect position through the end wall, such means consisting of a flange and groove rigid interconnection between the end wall and each of the tracks, the flange and groove interconnections providing the sole interconnections between the side walls and end wall and being such that loads on one side wall are resisted by both side walls acting in combination with the end wall; and f. wherein each side wall has a lower and an upper section hinged together such that one section is capable of folding over the other section into a collapsed position, and means is provided to rigidly couple the two sections together in the erect position.
 2. The cargo container claimed in claim 1 wherein the rigid coupling means comprises a doubler affixed to one of the sections and adapted to be rigidly secured to the other section when the side walls are erected.
 3. The cargo container claimed in claim 2 wherein an upstanding doubler attached to the base is provided for each side wall and means is provided to rigidly couple the lower sections of the side walls to such upstanding doublers.
 4. A collapsible cargo container for use in aircraft comprising: a. a base to support cargo; b. first and second spaced-apart and rigid side walls, each side wall being coupled to the base for selective positioning in a stored position overlying the base and an erect position substantially normal to the base and parallel to the other side wall; c. a track on each side wall, each track being disposed about at least a substantial portion of the edge of its associated side wall; d. first and second end walls formed of individual rigid slats flexibly interconnected along adjacent lengthwise edges, the end walls being removably and slidably disposable in the tracks of the erected side walls with the slats normal to the side walls, the end walls being capable of bounding substantially the entire ends and top of the container in a closed position; e. means associated with the tracks and the end walls to rigidly and nonrotationally couple the side walls together in their erect position through the end walls, such means consisting of a flange and groove rigid connection between the end walls and each of the tracks, the flange and groove connections providing the sole interconnections between the side walls and the end walls and being such that loads on one side wall are resisted by the side walls acting in combination with the complementary end walls; and f. wherein each side wall has a lower and an upper section coupled together such that one section is capable of being folded over the other section in the stored side wall position, and means is provided to rigidly couple the two sections together in the erect position.
 5. The cargo container claimed in claim 4 wherein an overcap is provided for each track, the overcaps having a recess disposed to permit each end wall to be moved from its closed position to a position overlying the other end wall and resting on the overcap associated with such other end wall.
 6. The cargo container claimed in claim 5 including a ridge beAm, the ridge beam being removably disposable in the recess of the overcaps and between the side walls, the ridge beam providing guiding surfaces for the end walls during their removal from and insertion in the tracks.
 7. The cargo container claimed in claim 5 wherein the coupling of the side walls to the base is provided by hinge means between the lower sections of the side walls and the base, and means is provided to nonrotationally couple the side walls to the base in their erect position.
 8. The cargo container claimed in claim 7 wherein a track extension for the end walls is provided below the hinge connection of the lower sections of the end walls to the base, the lower end of the overcaps and tracks and the upper end of the track extensions defining a slot for removing and placing the end walls from and into a stored position overlying the base.
 9. The cargo container claimed in claim 8 wherein the hinge connections of the lower sections of the end walls to the base are such that the side walls in their stored position are spaced from the base to provide a space for storage of the end walls.
 10. The cargo container claimed in claim 9 wherein upstanding doublers are provided on the base, the doublers being canted slightly outward from the vertical to provide ease of side wall erection, the nonrotational coupling means including the doublers and fastening means to rigidly attach the side walls to the doublers.
 11. The cargo container claimed in claim 5 wherein each end wall slat is provided with an underlying lip extending along one longitudinal edge thereof and an overlying lip extending along the other longitudinal edge thereof, the overlying and underlying lips of adjoining slats being disposed with each other to provide a weatherproof, flexible joint between slats.
 12. The cargo container claimed in claim 5 wherein the slats of the end walls are longitudinally rigidly interconnected.
 13. The cargo container claimed in claim 12 wherein the rigid coupling means includes flange and groove connections between the slats and the tracks, the flange and groove connections being such that loads on one side wall are resisted by the side walls acting in combination with the complementary end walls.
 14. The cargo container claimed in claim 13 wherein the flange and groove connections are provided by a continuous groove in end sections of the slats and a continuous mating flange of the tracks.
 15. The cargo container claimed in claim 13 wherein the flange and groove connections are provided by continuous grooves of the tracks and mating flanges on end sections of the slats.
 16. The cargo container claimed in claim 14 wherein the overcaps have an upstanding flange adapted to mate with the groove of the slats to provide a positive track for the end walls disposed on the overcaps.
 17. The cargo container claimed in claim 5 wherein the rigid coupling means includes rollers disposed in grooves having bearing edges engageable with the rollers to transmit loads from the side walls to the slats. 